Back to results
US 11,145,318 B2Granted
Audio encoder and decoder for interleaved waveform coding
AssigneeDolby International AB
InventorsKristofer Kjoerling, Robin Thesing, Harald Mundt, Heiko Purnhagen, Karl Jonas Roeden
Life of this patent
Estimating the term…
Abstract
There is provided methods and apparatuses for decoding and encoding of audio signals. In particular, a method for decoding includes receiving a waveform-coded signal having a spectral content corresponding to a subset of the frequency range above a cross-over frequency. The waveform-coded signal is interleaved with a parametric high frequency reconstruction of the audio signal above the cross-over frequency. In this way an improved reconstruction of the high frequency bands of the audio signal is achieved.
Claims15
A method for decoding an audio signal in an audio processing system, the audio signal comprising a plurality of frames and each frame including two or more time ranges, the method comprising:
- receiving, for a particular frame of the audio signal, a first waveform-coded audio signal having a spectral content for a first frequency range of the audio signal up to a cross-over frequency;
- receiving, for the particular frame of the audio signal, a second waveform-coded audio signal comprising spectral content for a subset of a second frequency range of the audio signal above the cross-over frequency;
- receiving, for the particular frame of the audio signal, a control signal comprising data relating to a subset of the two or more time ranges in the particular frame of the audio signal for which the second waveform-coded signal is available, and one or more frequency ranges above the cross-over frequency for which the second waveform-coded signal is available;
- receiving frequency reconstruction parameters;
- performing frequency reconstruction using at least a portion of the first waveform-coded signal and the frequency reconstruction parameters so as to generate a frequency reconstructed signal comprising spectral content in the second frequency range above the cross-over frequency, wherein for at least one of the two or more time ranges the frequency reconstructed signal is for a third frequency range that is lower than the subset of the second frequency range in the particular frame of the audio signal;
- and
- interleaving, in the particular frame of the audio signal, the frequency reconstructed signal with the second waveform-coded signal based on the control signal, wherein the audio processing system is implemented at least in part with hardware.
4 more elements
An audio decoder for decoding an encoded audio signal, the audio decoder comprising:
- an input interface configured to receive a first waveform-coded audio signal having a spectral content for a first frequency range of the audio signal up to a cross-over frequency, wherein the audio signal comprises a plurality of frames and each frame comprises two or more time ranges, a second waveform-coded audio signal comprising spectral content for a subset of a second frequency range above the cross-over frequency, a control signal comprising data relating to a subset of the two or more time ranges in a particular frame of the audio signal for which the second waveform-coded signal is available and one or more frequency ranges above the cross-over frequency for which the second waveform-coded signal is available, and high frequency reconstruction parameters;
- a frequency reconstructor configured to receive the first waveform-coded signal and the frequency reconstruction parameters from the input interface and to perform frequency reconstruction using the first waveform-coded signal and the frequency reconstruction parameters so as to generate a frequency reconstructed signal comprising spectral content above the cross-over frequency, wherein for at least one of the two or more time ranges the frequency reconstructed signal is in a third frequency range that is lower than the subset of the second frequency range in the particular frame of the audio signal;
- and
- an interleaver configured to receive the frequency reconstructed signal from the frequency reconstructor and the second waveform-coded signal from the input interface, and to interleave the frequency reconstructed signal with the second waveform-coded signal based on the control signal.
1 more element
An encoding method in an audio processing system, comprising the steps of:
- receiving an audio signal to be encoded, the audio signal comprising a plurality of frames and each frame comprises two or more time ranges;
- identifying, based on the received audio signal, a subset of a frequency range above a cross-over frequency for which spectral content of the received audio signal is to be waveform-coded;
- generating a first waveform-coded signal by waveform-coding the received audio signal for spectral bands for a first frequency range of the audio signal up to the cross-over frequency, a second waveform-coded signal by waveform-coding the received audio signal for spectral bands corresponding to the identified subset of the second frequency range above the cross-over frequency, and a control signal comprising data relating to a subset of the two or more time ranges in a particular frame of the audio signal for which the second waveform-coded signal is available and one or more frequency ranges above the cross-over frequency for which the second waveform-coded signal is available;
- and
- calculating, based on the received audio signal, frequency reconstruction parameters enabling frequency reconstruction, of the received audio signal above the cross-over frequency, wherein said frequency reconstruction uses the first waveform-coded signal and the frequency reconstruction parameters so as to generate a frequency reconstructed signal comprising spectral content above the cross-over frequency and the frequency reconstructed signal is to be interleaved with the second waveform-coded signal based on the control signal, wherein for at least one of the two or more time ranges the frequency reconstructed signal is in a third frequency range that is lower than the subset of the second frequency range in the particular frame of the audio signal.
2 more elements
Dependencies are inferred from the claim text.